Electric solenoid



Nov. 29, 1 27. 1,650,799

T. L. LEE 7 ELECTRIC SOLENOIDS Filed May 1924 Eng IL Fig 21 llnvcemtqm,

Emmi-I Patented Nov. 29, 192?.

THOMAS L. LEE, 0E RQCHESTER, NEW YQRK, ASSIGNOR TO NORTH EAST ELECTRICCOMPANY, 016 ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

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Application filed May 17, 1924. Serial No. 714,136.

The object of this invention is to produce an electric solenoid magnetof compact and efficient form, with a structure which is inexpensive,easy to assemble, and yet rugged.

To the foregoing end the invention consists in the solenoid illustratedin the accompany ing drawings and hereinafter described, as it isdefined in the attached claims.

Tn the drawings Fig. 1 is a cross-section of a solenoid embodying thepresent invention on the line 11 in Fig. 2, and Fig. 2 is a longitudinalsection of the same.

The illustrated embodiment of the invention comprises a base-plate 5, ofsheet steel or iron, provided with perforated lugs 6 by which it maybeattached wherever the solenoid is to be used. The base-plate, togetherwith a cup-shaped shell 7, also of steel or iron, constitute a housingfor the other parts of the solenoid. To secure these members together,and toprovide also a.

guide for the plunger, the base-plate is centrally perforated andprovided with an integral neck 8 in which one end of a centralguide-tube 9 is fitted, the end of the tube being flanged over as shown.The guide-tube is of brass or other non-magnetic material.

At the upper end of the guide-tube is a plug 10 of iron or steel, whichis grooved circumferentially and is fixed in place in the tube by a head11, in the wall of the tube, pressed or rolled into the groove. Thisplug is engaged by a screw 12, passing through the 1shell 7, and througha plate 13 of iron or stee The winding 14 of the solenoid is enclosedwithin the shell. The armature or plunger 15 slides within theguide-tube, and is provided, at the top, with a bufi'er life-ofnonmagnetic material. A spring 17, seated in perforations in the plug 10and the plunger, tends to move the plun er in the opposite direction tothat in whic it moves when the solenoid isenergized. The plunger may beconnected, as by a rod 18, with any part or device which is to beactuated by it.

It will be apparent that an eficient magnetic circuit is providedthrough the base, the shell, the plug 10 and the plunger. The plate 13is used to increase the permanence of the circuit at a point where thecrosssectional area of the metal would otherwise be relatively small.The neck 8 on the baseplate serves to reduce the reluctance at the gapbetween the base and the plunger, and also to provide an extendedsupport for the guide-tube.

The assembling of the solenoid is simple, as all of the parts gotogether loosely, and are then drawn into firm engagement by the singlescrew at the top.

The invention claimed is:

1. A solenoid comprising: a centrally perforated plate of magneticmaterial; a guide tube, of non-magnetic material, outwardly flanged atone end and closed, at the other end, by a plug of magnetic materialfixed to the guide-tube, the guide-tube being seated, at its flangedend, in the perforation in said plate; a winding surrounding the guidetube; a cup-shaped shell, of magnetic material, enclosing the windingand resting, at its edge, against said plate; and screwthreaded meansconnecting the closed end of the shell with said plug in the guide-tube,whereby the shell and the base-plate are secured together through theagency of the plug and the guide-tube.

2. A solenoid comprising: a base-plate with a central opening andintegral neck at said opening; a guide-tube seated in and secured tosaid neck, said tube being of nonmagnetic material; a plug, of magneticmaterial, fixed in the end of the guide-tube re mote from thebase-plate; a winding surrounding the guide-tube; a cup-shaped shell ofmagnetic material, enclosing the winding; and a screw passing throughthe closed end of the shell and threaded into said plug, whereby theshell and the base-plate aresecured together through the agency of theplug and the guide-tube.

THOMAS L. LEE.

